Otis tufts



PATENTED DEG. 11, 1866.

0. TUPTS. ELEVATOR.

I rave/7o 50 7;

the drum st nt A fit-ts.

rursovsusnr IN ELEVATORS;

(the fittest: Ititlffth to in that Blotters has cut making out Mitt filmlt.

TO ALL WHOM IT MAY CONCERN Be it known that I, CITIS TUFTS, of Boston, in the county of Suifolk, and State of Massachusetts, have invented an Improvement in Elevators and I do hereby declare that tlIG fOllOWlHg, taken in connection with the drawings which accompany and form part of thisspecification,'is a description of my invention sufficient to enable those skilled in the art to practise it. I

Where two or more suspensions of an elevator car are used it becomes very desirable, in order to secure their maximum wear and durability, to adjust the length thereof between their points of attachment to the winding drum and the car in such a way as thereby to cause each suspensory to take its proportionate share of the whole strain. Especially is some such'adjustment necessary where but two suspensories are used in connection with a car or platform suspended from its top, and having long guides working on ways,'to guide the car in a substantially vertical direction, for when one of said suspensories breaks, or becomes slack, the tendency of the car or platform is to swing on the other, so as to bring its centre of gravity in line therewith, causing great strain onthe ways and guides, which is liable to result in binding of the car on the ways, and in the general derangement or breakage of the parts. p

In the' United States Letters Patent granted to me on the 28th of May, 1861, I there set forth the advantagcs, for the purposes of increased safety and durability, of the employment, in connection with elevator cars,

of two or more ropes or chains, having independent attachments of each to the car and to the winding drum,

vand I described in my said patent means for the simultaneous automatic adjustment of each of the series of ropes used to hoist and lower an elevator car.

I have foundin practice how (liflieult itis to out two or more long ropes of wire or other material, or two or more chains, to the same exact length, and also how diflicultit is to so make the independent attachments of each of the ends of each of the series of ropes or chains, as that when attachedv with one end to the windin drum, and the other to the car, there shall be the same exact length between the two points of attachment of each of the ropes or chains, and thesame, or very nearly the same, tension on each rope or chain.

I In many instances, considerations of saving in the first ccst'oi' construction render it desirable to slibstitute for an automatic adjustment of the ropes'or chains a means for adjusting them from time to time, as occasion may require, by which, Within certain limits, lack of, uniformity in the tension thereof, or in the length between the points of attachment of the ropes or chains, is prevented from becoming prejudicial thereto in the matters of increased safety and durability. I havethereforefound it a matter of convenience, in construction of elevators, and of; utility in the working thereof, to combine with a winding-drum, with a serie's of-ropes or chains, and with the car of an elevator, means formanipulatory relative adjustment, within reasonable limits,

of the series of ropes or chains, which are independently attached to the winding. drum and to the car of the elevator, so that an equal. degree, or very nearly equal degree, of tension can be had upon each rope or chain of the series, by proper attention and manipulaticn on the part of the party having such an elevator in charge.

It is in the combination just before stated, when arranged to operate substantially as described, that one partof my invention, herein set forth, consists.

Another part consists in making use of intermediatedevices, secured to the ropes, and made adjustable with reference to the drum or the car.

And another part consists in constructing the winding drum with two'rope bed-curves, each. the opposite of the other, so that however the winding druin may be turned, the rope cannot be bent to an angle on or in In the drawings, illustrating an embodiment of my inventiou I Figure 1 shows in side view one form of a device for adjusting the length of one of the ropes or chains and its tension relative to the other rope or chain or chains by which the ear'is suspended; and

ll'ignre 2 showsin'section similar devices, applied to two ropesor chains, this being the smallest number of tensile supports whieh'admits of adjustmentrelative to each other. 4

In'the drawing a represents thecar, which is hung by its top from the ropes or chains b, which pass over the guide pulley a, and thence tothe winding drum (1, the cafbeing guided in its movements by slides fix'ed t the timbers or frame e. Devices by which the length and tension upon the ropes can be adjusted are shown as connected to the drum d, though they might be attached to the top of the car instead, or even inserted in the ropes or chains in parts whieh do-not turn over or wind upon either the guide pulley or the winding drum.

Many different devices may be employed asthe means for the relative mechanical manipulatory adjustment of thefiexible supports in the combination .claimed herein as my invention, and I would here remark, that however the form of this element of my combination may be changed, the element itself will remain so long as means are found for exact relative mechanical adjustment, by manipulation, of the length of one or more of the ropes or chains between their separately attached ends. The means shown are the best known to me for.

the embodiment of this element, and are as follows: is a tubular screw, one part of its bore being f proper diameter to just receive the rope or chain, while the other part of the bore is enlarged, as shown in fig. 2, to receive an enlargement of the rope or chain by which one end of the same is secured to the drum. Fixed to the winding drum are guides g g, which, in connection with thepiece h, keep the tubular screw-f from turning as the nuts 2' 2' are turned to move the-screwf, in one or the other direction, the ends of the slides serving as beds for the nuts. The passage way for the rope through the drum on its way to the adjusting device is curved in-betir-directions, as seen at j j, so that, especially where wire ropeis used, the drum may be rotated in either I direction without injury to the rope, the radius of the ropebed-curves being comparatively large.

With ropes or chains used together in a series of two or more, forthe purpose of hoisting and lowering an elevator car, each rope or chain having its ends'independently attached, one of said ropes or chains may have its ends so attached without means for adjustment, in which case the other tensile support 01 supports will have to be adjusted, as to length and tension, with relation to the rope or chain which is lacking the means of facile adjustment. I Y

I claimattachment of a suspending rope of an elevator car by means of an intermediate device f, adjustable with reference to the car or drum, substantially as described.

Also, in combination with an elevator car, its winding drum, and two or more ropes or chains for hoisting and lowering the car, means for relative mechanical manipulatory adjustment of the length and tension of said ropes or chains, arranged-to operate substantially as described. I Also, in combination with a winding drum, of two rope bed-curves, reversed in position with respect to each other, as set forth. OTIS TUFTS.

Witnesses 2 J. B. CnosBY, W. B. Grinssolv. 

